Lightning-arrester



(No Model.)

A. G. WATERHOUSE. LIGHTNING ARRESTER.

No. 475,645. Patented May 24,41892.

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UNITED STATES PATENT OFFICE.

ADDISON G. VVATERHOUSE, OF HARTFORD, CONNECTICUT.

LIG HTNING-ARRESTER.

SPECIFICATION forming part of Letters Patent No. 475,645, dated May 24, 1892.

Application filed December 17, 1891. Serial No. 415,419. (No model.)

To au whom it may concern,.-

Be it known that I, ADDIsoN G. WATER- HOUSE, a citizen of the United States, residing at the city of I-Iartford, in the State of Connecticut, have invented new and useful Improvements in Lightning-Arresters for Protecting Dynamo-Electric Machines, of which the following is a specication.

My invention consists of a lghtnng-arrester having means for conducting abnormal electrical currents to the earth, which may be communicated to the couductors of a dynamoelectric machine by lightnin g or other source of electrical energy, which I will call lightning discharges, and a means for temporarily short-circuiting the field-magnets or suspending the current-producng capacity of the dvnamo-electrical machine while said discharges are passing to the earth and until after said discharge is broken, which would during its continuance offer a path for the current of the dynamo-electric machine.

Figure 1 shows, diagrammatically, a dynamo-eleetric machine of the derived circuit type with a lightning-protector embodying my invention adapted for nterruptng the current which passes through the field-magnet coil. Fig. 2 shows a modified form of my invention adapted for short-circutng thefieldmagnet coil as applied to a derived-circuit Fig. 3 shows a form adapted to short-circuiting the field-magnet coil of a series-wound type of a machine by having plate K connected at any convenient place on the working circuit away from the dynamo. Fig. 4 shows a form in which the lightning-protector is adapted for interrupting the current in the field-magnet coils of a series-wound machine and at the same time creating apath for the current around said fieldmagnet. Figs. 5, 6, and 7 are modified forms ot' myinvention. Fig. S is a detal.

Fig. 1 shows, diagrammatically, a dynanoelectric machine with appliances embodying my invention. in which A is the armature, having contact-brushes B and O, and maincircuit couductors B' and O' leading therefrom and forming the working circuit; also, a derived-circuit field-magnet coil F, extending from brush B to C. There is placed in this circuit a circuit-breaker conssting of the movable armature f and stationary contactpoint g. The armature f is electrically connected to the field-circuit F and rests upon g, and conpletes the circuit leading to brush O. Above f is placed an electro-magnet II, which is adapted to raise the armature f from g and break the field-circuit F, Connected to main couductors O' is a wire leading to and around the magnet Il and then to the flashing-plate K. Near K is placed a second plate L, with connection leading to the earth E. \Vhen an electric discharge enters on wire O', it passes around magnet H to plate K, then to L, and the earth E. In doing so it energizcs magnet II, and, lifting f, breaks the field-circuit, which interrupts the current passing through the field-magnet coil and steps the current-producing energy of the dynamo until the are formed between plates K and L is broken.

Fig. 2 shows a form in which the energy of the machine is nterrupted by short-circuiting the field-magnet coil F. In this case I will suppose the lightning-discharge ente's on main line C'. In doing so it passes on the wire leading to the plate K, then arcs across and passes to the plate L and earth E. In forming an arc between K and L the pointer M, owing to its position, is inclosed by the flame of the are. This would form a circuit around the armature A, starting at point M', and which includes the are between plate K and pointer M and also the resistance R, used in series with the field-coils F, which resistance would be sufficient to oppose the building up of too great a current, because at the same time the circuit formed from M' via M and K to brush C, including resistance R, would form a shunt around the field-magnet coil F and divert the current from passing that way until by interrupting the force of the dynamo the are between K and L, and consequently the are between K and M, would break.

Fig. 3 shows an application of the same de- Vice in the case of a series-wound dynano where the lightning-discharge passing in on line P would follow the conductor leading to plate K, then are across to plate L, and pass to the earth E. In doing so it would inclose pointer M in the arc-fiame and form a short circuit around the field-magnet coil F wa line P, plate K, pointer M, and brush IOO B. This would consequently paralyze the field-coils and stop the current until the are between plates K and L breaks.

Fig. 4: shows a series-wound dynamo having a circuit-breaker in the line between tle armature A and field-magnet coil F. This circuit-breaker is conposed of the movable arnature f and stationary contact-point J. When an electrical discharge enters on line C' and arcs from plate K to L, it forns a circuit to M and on the conductor H', leading from M to the electro-magnet II, and then on wire 11 to contact P'. This completely shunts the field-magnct F and at the same time causes the magnet H to raise the armature f from contact-point g', thereby interrupting the current passing around the field-nagnct coil F.

Fig. 5 shows a form in which an electrical discharge entering on wire P goes to the earth E @ia line K' and by plates K and L to E. The arc forned between K and L surrounds pointer M and forms a circuit via line K', plate K to M, and online M' to brush B. This completely short-circuits the field-magnet coil F and steps the current until the are between plates K and L is broken.

Fig. G shows a double set of flashing-plates K, L, M, and MC Plate K is connected to line C', plate M to brush B, and plate M' to P', which would form a circuit which would exclude the field-magnet F if plates M and M' were connected. It is plain if an electrical discharge entered eitherfron line C' or from point P' in passing to plate L it would cause a fiash which would short-circuit plates M and M' and by paralyzing the field-coil F stop the current until the are between any two of the plates was broken.

Fig. 7 shows a series machine arranged so that if a discharge enters from wire C' to plate K and arcs to plate L in going to E it forms a circuit around the armature wa brush C, wire 0 plate K, pointer M, wire M', and resistance R to brush B. This circuit excludes the field-magnet coil F and stops the current until the are between the plates K and L and pointer M is broken.

Fig. 8 shows any form of construction in which the pointer M is made in the form of a plate so adjusted that a discharge from K would jump to plate M and then over to plate L in order to reach from plate K to L.

I have shown that the circuit formed by the pointer M can be used for destroying the field magnetism of a dynamo; but it is also plain that the new circuit formed from pointer M can be used to do other kinds of work, such as working an electro-magnet, which will break the working circuit of the nachine.

What I claim as my invention is- 1. A lightning-arrester composed of three flash-plates, one of which is electrically connected to the earth and the other two connected to an electrical conductor at two places, which Would include work on said conductor between said two places of connection, said three flash-plates being adjusted in relation to each other so as to cause a flane produced byan electrical fiash in Crossing between two plates to include or envelop the third, substantially as and for the purposes set forth.

2. A lightning-arrester composed of three stationary fiasl1-plates, two of which are connected to the main circuit of a dynamo-eleo tric nachine at different points on the line and the third being electrically connected to the earth, substantially as described, and for the purposes set forth.

3. A lightning-arrester composed of three fiash-plates, one of which is electrically connected to the earth and the other two connected to an electrical conductor at two places, which would include work 011 said conductor between said two places of connection, said three flash-plates being adjusted in relation to each other so as to cause a flame produced by an electrical flash in crossing between two plates to include or envelop the third, said third plate being connected to said electrical conductor by means of aconductor, automatic switch, or circuit-breaking devices in said con-- ductor, adapted for interrupting or diverting the current in the main conductor, substantially as and for the purposes set forth.

4. A lightning-arrester conposed of three flash-plates adj usted in relation to each other, substantially as deseribed, one of said plates being electrically connected to the earth, a second being directly connected to an electrical conductor, and the third being electrically connected to the same conductor at a different point on its circuit, with switches or circuit-breaking devices in the conductor leading from the third plate, being adapted for interrupting or diverting the main-circuit current upon the passage of a current leading from said third plate, substantially as and 'for the purposes set forth.

5. A lightning-arrester composed of three fiash-plates adjusted in relation to each other, as described,one of which is connected to the earth, the second to a main-circuit conductor, and the third to the same main conductor at a different point by means of a conductor which would form a separate circuit or shunt around the parts of said main conductor between the points at which the second and third plate is connected, said third plate and its conductor being located so asto be brought in circuit by the fianie caused by a current passing from the second to the first plate, substantially as and for the purposes set forth.

G. A lightning-arrester composed of two main fiash-plates and one or more intermediate fiash-plates, one of said main flashplates being electrically connected tothe earth, the other main fiash-plate and the intermediate flash plate or plates each being electrically connected to an clectric conductor at different points on said conductor, which would include work, distance, or resistances between said points of connection, said main IOO IIO

and internediate flash-platcs being so adjusted in relation to each other as to cause a flane produced by an electrical flash in crossing between two of said plates to include or envolop one or all of the rest, substantially as and for the purposes set forth.

7. A lightning-arrester composed of two main fiash-plates and an internediate fiashplate, one of said main flash-plates being connected to the earth, the other main flashplate and the intermediate fiash-plate each being connected to an electrical conductor forning the field-magnet coil or coils of adynamoelectric machine at two points, which would include all or part of said field-nagnet coil or 

